1. Energy and Life
Chapter 8.1

2. Autotrophs vs. Heterotrophs
Energy comes from food
BUT most of foods energy comes from the sun
Plants/Animals use suns energy to obtain food
2 ways organisms obtain food
AUTOTROPH
HETEROTROPH

3. Autotrophs Use light energy from sun to make their own food
PLANTS, some BACTERIA

4. Heterotrophs
Obtain energy from foods they consume
Animals, humans

5. Traits that they share
Must release the energy from sugar and compounds to LIVE!
Get energy from sun
Autotrophs – directly
Heterotrophs – indirectly

7. Chemical Energy ATP is basic energy source for all cells
Energy can be stored in chemical compounds in organisms
Living things use chemical fuels
ATP – adenosine triphosphate
1 adenine
5 carbon sugar – ribose
3 phosphate groups (key to ATP’s ability to store/release energy
ATP is basic energy source for all cells
Like a charged battery!

8. Chemical Energy ATP (charged battery)
Energy stored in bonds between phosphates
Break one phosphate off & release energy
Cells use that energy for cellular activities
Now left with
ADP – partially charged battery

9. ATP Animation

10. ATP – Bill Nye

11. FYI ATP not stored in large quantities in cell because…..
Not a good molecule for storing energy
Glucose better for storing energy

12. WARM UP
What is the molecule we learned about yesterday that was a like a “charged battery”?
A. ADP
B. APP
C. Glucose
D. ATP

13. PHOTOSYNTHESIS
Ch. 8.2
PHOTOSYNTHESIS
Ch. 8.2

14. Photosynthesis Song

15. Photosynthesis
Photosynthesis – using energy of sunlight to convert water & CO2 into sugars, starches, and O2.
light
CO2 + H20  C6H O2
(Carbon dioxide + water  glucose + oxygen)
Carbon dioxide comes from air or water

16. Light and pigments Water & carbon dioxide
Low energy materials
They turn low energy raw materials into high energy sugars using….
Using Light and pigments

17. Light Sun’s energy is in form of light
Sunlight is a mixture of different wavelengths of light
Visible spectrum – visible to eye
Different colors of light = different wavelengths

18. Pigments Pigment – light absorbing molecule
Chlorophyll main pigment for plants
2 main types
Chlorophyll a
Chlorophyll b
Chlorophyll absorbs
blue-violet and red regions of visible spectrum
Chlorophyll does not absorb
Green region of visible spectrum
Carotene another type of pigment
Red and orange pigment

19. Pigments and energy
When you absorbs light, also absorb energy from that light
When chlorophyll absorbs light
Energy transferred to electrons in chlorophyll
raises energy levels of electrons
High energy electrons make photosynthesis work.